The invention relates to a magnetic separator according to the precharacterizing clause of claim 1. Such magnetic separators are used in chemical and molecular biological analysis for separating specific substances from a solution. Said substances, in a sample vessel or the like, become attached to ferromagnetic particles which are manipulated by means of a magnetic field.
EP-A-0 497 448 discloses a magnetic separator of the generic type, having a fixed holder for a titre plate and a magnetic arrangement vertically displaceable between an active position and a passive position by means of four levers actuatable by means of push rods. However, it is not possible to remove the sample liquid within the magnetic separator completely from the vicinity of the magnetic arrangement and to feed it, for example, to a treatment of another type, which however is necessary in the case of many applications. If, for example, the sample liquid is to be heated, a separate heating station must be provided and the titre plate must be moved between the magnetic separator and the heating station. Either this must be done manually, which is not desirable for various reasons, or appropriate transport means must be provided. Any transport means present will be blocked for a relatively long time by the transport of the titre plate and will not be available for other tasks. In addition, the magnetic separator is suitable only for sample liquid containers of one type.
Another magnetic separator is disclosed in U.S. Pat. No. 5,443,791. Here, a washing means which has a heatable and coolable metal plate for holding sample liquid containers, below which plate a vertically displaceable magnetic arrangement is mounted, is provided in the frame of a workstation. This arrangement in which a further function has been integrated in the magnetic separator without spatial separation has the disadvantage that the magnets are exposed to relatively high temperatures, which is harmful especially for permanent magnets and reduces their efficiency. Moreover, the structure of the station is relatively complicated and the suitability is likewise restricted to sample liquid containers of one type.
It is the object of the invention to provide a magnetic separator in which the sample liquid can be completely removed from the vicinity of the magnetic arrangement.
This object is achieved by the features in the characterizing clause of claim 1. The invention provides a compact magnetic separator which has a relatively simple structure and with which it is possible to subject the sample liquid to other processing steps, in particular to heat it, without troublesome interactions with the magnetic arrangements occurring. The magnetic separator according to the invention can be formed in such a way that all steps required in specific processes can be carried out therein without modules or external transport means additionally being required. It can also be converted by slight modifications, for sample liquid containers of a different type and size, it also being possible to handle relatively large containers.
The magnetic separator according to the invention can be very readily installed in a relatively large workstation with further modules and transport means, such as, for example, a robot arm which is also used for pipetting and otherwise. During the sequences of functions in the magnetic separator, the transport means thereof are not used and are completely available for their other functions.